If one were to be very technical, the filter's output flow could easily be considered a series of harmonics based on the rotational frequencies and the water pressure pulses each blade of the pump produces
in practical terms we don't even need to go there, viewing it as a uniform flow is much more appropriate. I don't think we should even be thinking of the flow as waves, more like uniform particles coming out. You are talking about super positioning and cancellation effects of waves, not required for our objectives. The scale of effect is way too small to be even appreciable, and with newer pumps (not on commercial canisters mind) that operate at much higher rpms this effects is basically nil and can be treated as totally linear.
Flow in the tank is non-linear in the sense that it is possible that the unit volume passes a given point multiple times before leaving the tank - where it later returns. This is clearly cyclic and therefore, a harmonic analogy is absolutely appropriate.
I'm more concerned about the fluid dynamical effects that are happening than anything to do with harmonics or resonance. The question one should ask is the obvious, if there was such a point where the flow goes around itself is it localising the water or is it a, how shall I say, temporary holding area where the water gets moved on anyway. If it is the latter, we wouldn't care (well maybe the fish would care!), if the former then that would imply that whatever gets trapped gets localised and hence will never move from there creating a "holding area".
I've looked at Amano's tanks and he does nothing fancy - he doesn't need to. There's nothing fancy in this apart from using common sense. But there is a fine dividing line between having good flow around the tank to create a constant spring cleaning effect or blasting the hell out of everything.
If your objective is to make sure that the water is being mixed well to give immediate dilution effect then relatively low flow can achieve this as long as you strategically place the outputs right (and this requires experimenting). If we are talking about creating enough flow so that detritus gets swept into the currents and ends up getting sucked up in inlets of the canister filter then that is a different proposition altogether.